A conventional test handler comprises a turret and pick heads coupled to the turret for holding semiconductor packages. During operation, the turret rotates above various modules or handling devices of various functions, such as a testing module for testing the performance of the semiconductor packages. A pick head holding a semiconductor package moves to a module or a handling device to perform the functionality of the handling device on the semiconductor package. Specifically, the pick head holding the semiconductor package moves to the testing module in order to test the semiconductor package. In particular, the testing module has to be aligned with respect to each semiconductor package which is held by the respective pick head, in order to achieve good machine stability, a high function test yield, and a low rate of package damage.
At present, the alignment or positional adjustment between the testing module and the semiconductor packages is achieved by using human judgment such as for free adjustment or by using a mechanical jig. Since human judgment is subjective and requires the operation of the test handler to be visualized, it becomes difficult or even impossible to perform manual adjustment if the size of the semiconductor packages is very small. Additionally, this method requires considerable human skill and labour, due to an absence of data on which accuracy may be based.
In one prior art approach, a vision assist module alignment method makes use of an optical device mounted to a turret, and a plurality of imaging devices to first align a fiducial mark and to subsequently align a position of a handling device. However, such an approach requires several alignment steps involving multiple imaging devices. In addition, the optical device increases the weight of the turret and thus, reduces the operation speed of the turret. As a consequence, system throughput is also undesirably decreased.
Thus, there exists a need for an apparatus for handling electronic components, and a method of adjusting the position of at least one handling device of an apparatus for handling electronic components, that seek to address at least one of the above problems.